1. Technical Field
The field of this invention is switches and, in particular, multi-directional, multiple switch assemblies such as those found in electronic game device handsets or remote control devices for televisions.
2. Description of the Prior Art
In electronic video game devices, a handset is typically provided for controlling the action of the game as it appears on the television screen or monitor. These handsets include various switches including pushbutton switches and directional switches. As shown in FIG. 1, the directional switch assembly, generally indicated at 10, typically has four switches, 12, 14, 16, 18, one for each direction, East, West, North and South. Each switch consist of a moveable contact or conductive rubber pad 20, sometimes called "pucks" due to the miniature "hockey puck" appearance, which are positioned over corresponding stationary contacts 22 formed of conductive fingers 24 on a printed circuit board or support 26 located in the handset. The stationary contacts 22 on the printed circuit board may be either plated copper or a conductive paint or ink which is applied by a printing process. By pressing a button or portion of an actuator 28 positioned over the moveable contact 20, the moveable contact 20, in its closed position, seats against its corresponding stationary contact 22 and closes a circuit between the conductive fingers 24 printed on the circuit board 26. In typical usage, each moveable contact 20 is individually supported by a silicone rubber membrane spring 30 which yields a consistent force profile as it is collapsed. The button which is pressed to close the switch is often molded in the surface of the rubber membrane opposite that of the conductive rubber pad, but a separate plastic actuator can be used as shown in FIG. 1. In a typical 4-direction assembly, the moveable contacts of all four switches are molded into the membrane to form a single directional assembly with one switch for each direction.
Typical forces to close a single switch range from 150 to 50 grams and the force profiles are relatively standard. The typical directional actuator, having the four directional switches, relies on four separate membrane switches which support the actuator. Because all four switches contact the actuator, all must be partially compressed to close one switch increasing the force actually required to close the switch beyond that required for a single switch. The magnitude of these closing forces has been alleged to cause repetitive stress injuries to the fingers and thumbs of game players of typical electronic games. To achieve reduced closing force very thin rubber membrane springs can be used. However, this reduces that amount of force available to return the moveable contact (i.e the puck) and the switch to the open position leading to unreliable switch operation. In addition, should the user provide excessive closing force, the switches adjacent the one intended to be closed may also close. This may cause an inaccurate action in the game being played or an incorrect response in the television set being controlled.
It would be advantageous to have a multidirectional switch assembly that has a lower actuation force. Further, it would also be advantageous to have a multidirectional switch assembly where on excessive closing force being applied to one of the switches the adjacent switches are not prone to close. It would also be advantageous to reduce the closing force for a switch without having to use very thin rubber membrane springs.